1. Field of the Invention
This invention relates to a measuring apparatus for measuring a charging degree of liquid, and more particularly to a measuring apparatus which is adapted to measure a charging degree of liquid used in the electric field as an insulated oil or in the petrochemical field.
2. Description of the Prior Art
It is well-known phenomenon the (so called fluidity-static electricity-phenomenon) that static electricity is generated by the fluidity of a fluid. In this case, the generation of the static electricity is changed according to the kind of liquid, water, oil, alcohol being one large classification and insulating oil, lubricating oil being another small classification.
Furthermore, even if the kind of liquid is the same, the generation of static electricity is changed by differences for example such or the difference between the mineral oil and the synthetic oil in the insulating oil used for a transformer, difference of quantity of annex, impurities, or difference of a little component, such as difference between new oil and old oil.
A method in which the charging degree of a liquid is determined by the electric conductivity of the liquid has often been utilized.
However, since it is confirmed that there is a case in which the generation of the static electricity is changed even if the electric conductivity of two liquids is same, and since the electric conductivity is not greatly changed if a component of two liquids generally differs a little in the same kind of the liquid, it is difficult to determine the charging degree of the liquid by using this method.
It should be readily apparent that a method in which the charging degree of the liquid is determined by using the dielectric loss tangent (or dielectric dissipation factor=tan .delta.) suffers from the same disadvantage.
Now, a method in which the liquid to be measured is compressed and the compressed liquid flows down in a container disposed between a pair of electrodes so as to cause the liquid to pass between the two electrodes has been utilized.
This method, however, suffers in that it is not easy to build an apparatus of the enclosed type and, therefore, is influenced by the environment no little.
Furthermore, in the event the charging degree of some kind of liquid is measured, it has the disadvantages that it is necessary to provide several measuring apparatuses, or that it is necessary many times to wash the used container after measuring.